Drilling mechanism



stares i i,a554,514 earner orties.

'rr-reali n. nnnnevrs'r, or cnanmvtorvfr, new Herarsrirnn, Assrenon 'ro SULLIVAN 'MACHINERY coiirrnnY, a conronafrron'or MASSACHUSETTS;

DRILLIN Gr ME CHANISM.

appncanon inea March 13, 1924. seri-@.1 Nm 599,112.

aiiisms.v

It has for its object to provide an improved drilling mechanism. A further object is to provide an improved drilling mechanism having improved means for increasing the efficiency of the drilling motor. Another object is to provide an improved drilling mechanism having a fluid actuated feeding mechanism andmeans associated withisaid latter means for increasing the operating e'ticiency of the drilling motor. A further object is to provide an improved constant pressure chamber within the feeding cylinder for the drilling motor. e

In the accompanying drawings 1 have shown for purposes of illustration one form which my invention may assume in practice.

iin these drawings- Fig. 1 is a side elevation partly broken away to show details of construction.

F ig. 2 is a fragmentary side elevation of the rear end of the feed piston rod.

F ig. 3 is a transverse section taken on linel 3-3' of Fig. 1.

Fig. et is an end elevation of Fig. 2.

Figy is a detail sectional view through the control valve showing the position of the several ports when the feed is reversed.

In the illustrative form of my invention I have shown the same embodied in a drifter type of drill, although it will be=obvious that any other type of drill may be used, and which comprises a combined shell and feed cylinder 1 having a depending bracket 2 adapted to engage any suitable support while extending upwardly therefrom are longitudinally disposed guidewa ys 3 within which the drilling mechanism, generally indicated at il, is slidably mounted. More specifically', the drilling mechanism comprises a usual percussive motor cylinder 5 havinga for- .wardly extending chuck housing 6 adapted lov carry a steel 7 while a rear cylinder head v 8 is fixed on the cylinder 5 as by any suitable side rod construction 9.

The feeding mechanism for my improved device comprises a rearwardly' extending hollow arm 10, herein shown as having a hollow portion 11 of considerable size, while formed in the upper and lower'sides thereof are longitudinal passages 12 and 13 respectively. The arm is disposed within a` conical bore 1l formed in the hollow portion of the head S and held therein as by a This invention relates to drilling mechthreadedy connection 15 adjacent the rear side of a vertical passage 16 which allows communication between the hollow portion: 11 and a main supply passage 17 leading to the drilling motor from a main control valve 18. The upper passage 12 hascom'munication with anupwardly extending passage 19 adapted to be vented to atmosphere when the valve 18 isin the position shown in Fig.

1 as by a groove 2O formed in the periphery of said valve.` The lower passage 13 communicates with a source of live pressurev fluid in the valve 18 as by an annular groove 21 formed in the forward reduced portion oit' the member 10 which communicates with a passage 22, groove 23 and portv24 leading to the interior of the valve 18, from whichv live pressure duid will dow. `Projecting downwardly from the rear end of the mem-V ber 10 is a member 25 having an annular recess 26 within which the member 10 seats and held therein by screws 27 threadedinto lugs 2S formed on the member 10. The lower portion of said member has a second i annular recess 29 within which the rear end of a hollow feed piston rod 30 is disposed and held therein by screws Sltlireaded into lugs 32 formed on', or welded to, the piston rod. The piston rod projects forwardly through a combined rear cylinder head and packing member v33 and carries 'at its forward end a piston 34, the front head of theA cylinder 1 y being closed by head 35. The hollow portion 11 in the member 10V has communication with the hollow portions 36 and 37 formed in the end of the member 25 and piston rod 30, respectively. Thesel hollow portions form a closed chamber within which live duid pressure is admitted onlylthrough the passage 16 and has such a capacity lthat pressure fluctuations inthe fluid conducting passage 17 will be reduced toa minimum, the

pressure fluctuations being reduced-due to y the factthat the pressure of the fluid within the hollow portions actsas a constant pres?v sure chamber. It will thus be seen that I have taken advantage of` already existing and necessary structure in a drilling mechanism to provide a suitable constant pressure chamber in which an additional source of pressure fluid may be stored. By my improved arrangement excessively large additional storage chambers are not required, thus keeping the weight of my device down to a minimum. 

